Cancer is a leading cause of death in the United States and the number of cancer deaths is growing. In 2014, the Institute of Medicine concluded that increasingly aggressive, burdensome and expensive end-of-life (EoL) care was a major public health problem that needed to be fixed. Dr. Prigerson's NCI-funded Coping with Cancer (CwC) studies point to potentially powerful psychosocial solutions to problems in the delivery of EoL cancer care. This R35 award will afford her the opportunity to translate the foundational observational research findings from her multi-site, longitudinal R01 CwC studies, funded continuously by NCI since 2002, into interventional trials to improve EoL cancer care. In Phase I of this program of research, Dr. Prigerson will develop the necessary research tools and build the capacity to advance the intervention development projects in Phase II. Specifically, Phase I projects will focus on the development and refinement of scales to assess targets and outcomes of psychosocial interventions in EoL cancer care, including a) patient and caregiver psychological readiness to process information communicated about prognosis (e.g., emotional acceptance of the patient's terminal prognosis); b) patient and caregiver understanding of illness and EoL treatment options (aka cognitive acceptance of the patient's terminal prognosis and EoL health literacy); and c) the patient's quality of life at the EoL (aka quality of death). PhaseI projects will also devise and establish databases that link existing CwC prospective cohort study data, and future psychosocial intervention trial data, to Medicare claims data to perform accurate, comprehensive evaluations of the impact of psychosocial factors and interventions on health service use and costs in EoL cancer care. Phase II projects will use these measurement tools and impact assessments to develop psychosocial interventions that target: a) illness and treatment understanding at the EoL, b) barriers to advance care planning, c) improvements in EoL outcomes, and d) reduction of racial, ethnic and gender disparities in EoL outcomes. Phase II projects will develop psychosocial interventions that incorporate and enhance proven strategies to promote emotional and cognitive acceptance of terminal illness and understanding of treatment options, apply notions of social proofing to improve EoL clinical communication, and contextualize religious beliefs (e.g., in miracles) to reduce disparities in EoL cancer care. This program of research is expected to yield novel and refined measurement tools for EoL cancer research, comprehensive datasets that link and relate psychosocial factors and interventions data to comprehensive health service use and costs data in EoL cancer care, and psychosocial interventions to promote understanding and better EoL outcomes for all cancer patients and their family members, regardless of their race, ethnicity or gender.